1. Field of the Invention
The present invention relates to circuits for canceling direct current (DC) offsets, and particularly to a circuit for canceling DC offset in a wireless communication system.
2. Description of Related Art
In wireless communication systems, a base band signal is modulated to a radio frequency (RF) signal via a modulator, and then coupled to an antenna and subsequently transmitted. During the process, DC offset can be generated in the modulator, which leads to energy consumption when the RF signal is transmitted. The DC offset is harmful for the communication systems. For example, in a mobile phone, lifetime of a battery is shortened by power loss due to the DC offset, thereby reducing standby time of the mobile phone.